Semiconductor devices often require accurate current sources to perform various electronic functions such as biasing, current amplification and timing. An ideal current source has a high output impedance, stable temperature operation and wide supply voltage compliance. One such device is a charge pump voltage converter. By using a capacitor as energy transferring element, a charge pump voltage converter produces an output voltage that is a multiple of its input voltage. For example, charge pump converters can convert a 5 volt input to a 10 volt output, a -5 volt output or a -10 volt output. These charge pump devices are often required to work over a wide input voltage range, thus the total voltage seen by the power supply of such devices varies substantially. Metal oxide semiconductor field effect transistors (MOSFETs) are used in such charge pump devices due to their excellent performance as a switching or logic element when the gate of the MOSFET is driven with a rail to rail logic signal. However, when a MOSFET is driven by a low gate voltage, it can exhibit excessive error current making it an unsatisfactory current source.